Figure 2. SEM images (A) and x-ray elemental maps of fluorine (B) and calcium (C) of the cross-section of the outer edge of composite disks containing 9.09, 23.08, and 33.33 mass% CaF2 after exposure for 4 mo in ambient air (control), and pH6 and pH4 buffer solutions. The white vertical bar in A represents 10 µm, and the white vertical bars in B and C represent 50 µm